Recommend using Close instead of OK (#8410)

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### WHY are these changes introduced?

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  Context about the problem that’s being addressed.
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When merchants need to dismiss a modal, they `Close` the modal. Today,
we use `OK` when merchants don't need to _officially accept_, but `OK`
is not an action. We should use language in buttons that better reflect
the action merchants need to take.

1️⃣ `Close` also translates well into other languages. 

2️⃣ `OK` does not translate super well. `OK` is often translated as:

<details>
<summary>
OK (just uses the English word)
</summary>
<img width="668" alt="italian"
src="https://user-images.githubusercontent.com/43160110/219497027-2480290f-d807-43c0-91b4-b40f93e30976.png">
</details>

<details>
<summary>
Okay (language-specific spelling of Okay, not OK)
</summary>
<img width="670" alt="16-01-ylzgp-iqq83"
src="https://user-images.githubusercontent.com/43160110/219498749-c60f0cbf-a648-44a0-9523-b7e36d3dfe97.png">

</details>

<details>
<summary>
Accept (eg. Aceptar in Spanish)
</summary>
<img width="664" alt="16-00-fay6k-ux1nx"
src="https://user-images.githubusercontent.com/43160110/219498903-d3c54159-5ca3-48c9-8e70-98e594f87e2e.png">
</details>


<details>
<summary>
Sure, Certain (eg. 确定 in Chinese)
</summary>

<img width="662" alt="chinese"
src="https://user-images.githubusercontent.com/43160110/219501039-166f9492-c5c6-4b97-be25-8de50f13f0cb.png">
</details>

`OK` has an ambiguous translation while `Close` does not. Let's use
`Close` to be more straightforward!

### WHAT is this pull request doing?

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      <img src="..." alt="Description of what the gif shows">
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### How to 🎩

🖥 [Local development
instructions](https://github.com/Shopify/polaris/blob/main/README.md#local-development)
🗒 [General tophatting
guidelines](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md)
📄 [Changelog
guidelines](https://github.com/Shopify/polaris/blob/main/.github/CONTRIBUTING.md#changelog)

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  Give as much information as needed to experiment with the component
  in the playground.
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<img width="1512" alt="Screenshot 2023-02-17 at 14 26 34"
src="https://user-images.githubusercontent.com/43160110/219805555-a55c4b3d-07a6-484d-bdb4-d77e3682692d.png">

<details>
<summary>
Desktop (Chrome)
</summary>
<img width="1512" alt="Screenshot 2023-02-17 at 14 26 34"
src="https://user-images.githubusercontent.com/43160110/219805555-a55c4b3d-07a6-484d-bdb4-d77e3682692d.png">
</details>


<details>
<summary>
Desktop (Safari)
</summary>
<img width="1512" alt="Screenshot 2023-02-17 at 14 32 56"
src="https://user-images.githubusercontent.com/43160110/219808123-1259f8e9-a43f-470a-8587-1633b2a6b398.png">

</details>

<details>
<summary>
iPhone 12 Pro
</summary>

<img width="1512" alt="Screenshot 2023-02-17 at 14 29 48"
src="https://user-images.githubusercontent.com/43160110/219806916-9ab6db1f-50bc-4410-9d21-78c56495d0c9.png">
<img width="1512" alt="Screenshot 2023-02-17 at 14 29 57"
src="https://user-images.githubusercontent.com/43160110/219806958-b26d653d-4fc3-40d6-b994-f0cd7f90548f.png">

</details>

<details>
<summary>
iPad Air
</summary>

<img width="1512" alt="Screenshot 2023-02-17 at 14 30 45"
src="https://user-images.githubusercontent.com/43160110/219807213-e26b894a-4fcf-447f-a01f-682b8d636734.png">


</details>


### 🎩 checklist

- [x] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [x] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [ ] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [x] Updated the component's `README.md` with documentation changes
- [x] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

---------

Co-authored-by: jjgali <77791660+jjgali@users.noreply.github.com>

Author: kellydanma

.changeset/witty-readers-glow.md

@@ -0,0 +1,5 @@
+---
+'polaris.shopify.com': patch
+---
+
+Use Close instead of OK

polaris.shopify.com/content/content/actionable-language.md

@@ -586,18 +586,21 @@ Use the adjective “Done” for datepickers.
 
 ---
 
-## OK vs. accept
+## Close vs. accept
 
-Use the adjective “OK” when merchants need to confirm they’ve read something, but aren’t required to legally accept terms of service before continuing. For example, use “OK” when presenting a security notification in a modal or sheet.
+Use the verb “Close” when merchants need to confirm they’ve read something, but aren’t required to legally accept terms of service before continuing. For example, use “Close” when presenting a security notification in a modal or sheet.
+
+Don't use "OK". "OK" is an exclamation, not an action. When merchants click the "Close" button, they’re not saying “OK”, they’re doing a specific action.
 
 <!-- dodont -->
 
 #### Do
 
-![modal with okay button spelled with capitalized letter O and K, no punctuation](/images/content/actionable-language/ok@2x.png)
+![modal with Close button](/images/content/actionable-language/modal-with-close@2x.png)
 
 #### Don’t
 
+- OK
 - Ok
 - O.k.
 - Okay
@@ -607,7 +610,7 @@ Use the adjective “OK” when merchants need to confirm they’ve read somethi
 
 <!-- end -->
 
-Use the adjective “Accept” when terms of service require legal confirmation before merchants can continue.
+Use the verb “Accept” when terms of service require legal confirmation before merchants can continue.
 
 <!-- dodont -->
 
@@ -619,6 +622,7 @@ Accept
 
 - Ok
 - Done
+- Close
 - Continue
 
 <!-- end -->